Orthodontic apparatus and method

ABSTRACT

An orthodontic device includes a bracket having a body and the body includes external surfaces. An archwire passageway is formed in the body. An aperture extends from one of the external surfaces of the body to the passageway. A pawl is attached to the body and includes stop and cam surfaces which extend into the aperture. An extendable archwire includes an adjustment portion having a locking surface and a loop-spring therein and the adjustment portion is inserted into and through the passageway. The pawl and the locking surface form a ratchet. The cam surface of the pawl interengages the extendable archwire as the extendable archwire is extended through the bracket under the application of force to the extendable archwire. The stop surface of the pawl interengages the locking surface of the adjustment portion of the extendable archwire preventing retraction of the extendable archwire upon discontinuation of the application of force.

This application is a Divisional Patent Application of U.S. patentapplication Ser. No. 11/697,729 filed Apr. 8, 2007 now U.S. Pat. No.7,837,466 and claims the benefit of, and priority to, that applicationand its filing date.

FIELD OF INVENTION

The present invention relates to the brackets and extendable archwiresused in the dental specialty of orthodontics.

BACKGROUND OF INVENTION

U.S. Pat. No. 7,033,171 to Wilkerson discloses, as set forth in theabstract thereof, the following: “[a] molar tube having a first faceportion that is adapted to be adhered to a molar tooth, a second faceportion, and a mesial-distal length dimension. There is a body portiondisposed on the second face portion of the base portion, and the bodyportion comprises an upper portion and a lower portion. The body portionfurther comprises a lumen that is adapted to receive an archwire,wherein the lumen has an axis which substantially coincides with themesial-distal length dimension of the base portion. The body portionfurther comprises a boss comprising a threaded bore that is adapted toreceive a setscrew, wherein the threaded bore has an axis. The axis ofthe threaded bore intersects with the mesial-distal length dimension toform an angle of any degree between 15 degrees and 55 degrees, includingevery degree therebetween. A molar tube according to the inventionallows for easy adjustment of the tension in an archwire used in anorthodontic dental treatment, and provides for the painless withdrawalof the archwire at any time during or following the treatment.” Easyadjustment of the tension as referred to in the '033 patent to Wilkersonrequires that the set screw be tightened while tension is applied to thearchwire by the orthodontist. Further, in the '033 patent to Wilkerson,no mention is made of measuring the tension in the archwire.

Orthodontics is the specialty of dentistry which focuses on thediagnosis, treatment planning, and treatment of dento-alveolar andskeletal malocclusions. In layman's terms orthodontics broadly andnonspecifically refers to straightening and positioning teeth for thehealth, comfort, safety and appearance of the patient.

The two major components of fixed orthodontic therapy are toothattachment mechanisms and archwires. Brackets and bands are used asattachment mechanisms. A band or a bracket may be attached to a tooth,either by cementing or bonding mediums. The purpose of the band or thebracket is to permit the health care provider to transfer a load orforce to a tooth or to a group of teeth in order to elicit orthodonticmovement of the selected tooth or teeth.

Two issues of concern in orthodontics are friction and management offorces. Although friction may have a positive effect in some instancesit is usually associated with detrimental effects. The reason for thisis that force which exceeds the ideal force necessary to move a tooth orteeth often must be employed to overcome various forms of friction whichare inherent in the biomechanics of sliding mechanics. Thus, thetendency is for sliding mechanics to tax anchorage units (causeundesirable movement of a tooth or teeth that are used in the process ofapplying forces to a tooth or teeth for which movement is desired).

By contrast, another form of orthodontic biomechanics is referred to aslooped mechanics. The “looped” in looped mechanics refers to a varietyof shapes of loops which are built into and are an integral part of thearchwire when it is constructed. The archwire is passive until the loopsare activated. The activated loops act as springs in that theydistribute a load through the orthodontic appliances to the tooth orteeth equal to the load of activation.

The load of activation is external to the patient's orthodontic system.Therefore anchorage is not compromised due to friction which isgenerated when sliding mechanics' techniques are employed for themovement of teeth. Frictional resistance is offset with forces externalto the closed orthodontic system without additional energy costs to theclosed system.

Orthodontists apply archwires and brackets as follows. First, bracketsare attached on one or more teeth. Then the archwire is inserted intothe brackets including the molar bracket tubes. The archwire is thenligated to one or more of the brackets. Force (tension) is then appliedto the archwire which then opens (activates) or otherwise changes thespring dimensionally which is formed in the archwire. Opening of thespring is also referred to herein as activating the loop spring.

Tension is then applied to the archwire to activate a loop spring.

While forcing the archwire into and through the lumen or passageway ofthe bracket the orthodontist makes an approximation or educated guessbased on experience as to whether or not enough force has been appliedto the archwire so as to properly treat the patient. The archwire isthen secured by bending it over the rear edge of the bracket to lock itin place.

At least two problems occur with this treatment structure andmethodology. First, the locking which takes place by bending thearchwire about the end of the bracket may become loose or disengagewhich then requires readjustment, re-locking or replacement of thearchwire. Second, the amount of tension (force) effectively applied tothe tooth or teeth is not known. Therefore, more visits to theorthodontist for adjustment and replacement are necessary. Additionalvisits to the orthodontist using present procedures is costly,inefficient and in some cases creates discomfort for the patient.

Therefore, it is highly desirable for an orthodontist to accurately knowthe force applied to a tooth or set of teeth. It is further highlydesirable for an orthodontist to securely lock the archwire in place andat the same time achieve the desired tension (force). It is furtherhighly desirable to enable the performance of clinical studies whereinthe results of the application of a known force can be observed andrecorded to assist in future treatment and diagnosis of patients.

SUMMARY OF THE INVENTION

The present invention is directed toward increasing the efficiency offorce applications in orthodontics and improving the control andmanagement of the forces. The present invention will additionallyimprove the ease of controlling and managing the forces.

It is one purpose of the invention to apply a precise load or force to aretraction or protraction archwire. The load or force dissipates as atooth or teeth move. The invention allows easy retrieval of theretraction or protraction archwire by the health care practitioner.

The application of a load is described hereinbelow.

The orthodontic bracket main body is secured to a base attachable orbonded to the surface of a tooth. The bracket main body may be welded,via the base, to a band attached to the surface of a tooth.

An exemplary embodiment of the invention includes an aperture or openingthrough an external surface of the bracket which extends through to theinternal surface of a bracket tube or slot. This aperture isdimensionally constructed to permit the insertion of a pawl into thetube or slot which when in the active position will permit a calibratedarchwire to slide in the desired direction. However, the calibratedarchwire is prohibited from sliding in the opposite direction unless thedevice is deactivated.

Another exemplary embodiment of the invention includes a pawl which iseither permanently or removably attached to the orthodontic bracket. Thepawl extends into the outer dimension of the bracket slot or tube andallows an extendable archwire to displace the pawl when the wire movesdistally. Another exemplary pawl extends beyond the perimeter of thebracket. The pawl includes cam and stop surfaces. When the cam surfaceis driven by the extendable archwire, the pawl is displaced outwardly.

In another exemplary embodiment of the invention, a portion of the pawlis designed to permit the use of an instrument or other facilitator todisengage the pawl from the extendable archwire. This may beaccomplished by mechanically disengaging the pawl from the extendablearchwire. This permits the retraction of the pawl extension from theactive or engaging position to an inactive or non-engaging position withthe use of an instrument or other facilitator and allows the easyremoval of the archwire.

An orthodontic device is disclosed and claimed which includes a brackethaving a body and the body includes external surfaces. An archwirepassageway is formed in the body and extends therethrough. An apertureextends from one of said external surfaces of said body to saidpassageway. A pawl is attached to the body and includes stop and camsurfaces. The pawl extends into the aperture of the bracket andinterengages the archwire.

The extendable archwire includes an adjustment portion having a lockingsurface and a loop spring therein. The adjustment portion of theextendable archwire is inserted into and through the passageway of thebracket and resides partially in the passageway of the bracket. Notchesor protrusions on the archwire interengage the pawl and prevent theextraction of the archwire from the bracket. The adjustment portion ofthe extendable archwire is selectively movable with respect to andwithin the passageway of the bracket.

The loop spring in the extendable archwire resists the extensionthereof. Upon the application of extension force the loop spring opensresulting in tension in the archwire. The loop under tension is said tobe activated. Force is applied to the extendable archwire by theorthodontist, pushing the archwire into and through the bracket and/orby pulling the archwire further out of the bracket once it has been fedinto and through the bracket.

Under the forces contemplated herein displacements are manifested byopening of the loop and no significant change in the cross-section ofthe archwire occurs. Put another way, the strain in the wire is minimal.

Loop springs in the extendable archwire may be in many different forms.It may be an open loop spring, a closed loop spring, a coil loop springor it may be assume practically any shape.

The loop spring would retract the extendable archwire upon thediscontinuation of the application of extension force by theorthodontist. However, the retraction of the archwire is prevented bythe interaction of the pawl with the notches and/or the protrusions inthe adjustment portion of the archwire.

The pawl of the bracket and the locking surface of the adjustmentportion of the extendable archwire form a ratchet. A cam surface of thepawl interengages the extendable archwire as the extendable archwire isextended through the bracket under the application of force to theextendable archwire. Stop surface of the pawl interengages the lockingsurface of the adjustment portion of the extendable archwire preventingretraction of the extendable archwire upon discontinuation of theapplication of external force.

A method for using the orthodontic device is also disclosed and claimed.The method includes attaching a bracket to a tooth. The bracket has apassageway therethrough and a pawl extends into the passageway. One endof the extendable archwire having a loop spring is attached to ananchor. The anchor may be a band, ligature or bracket. An adjustmentportion of the extendable archwire is inserted into and through thepassageway of the bracket. The adjustment portion includes lockingsurfaces which may reside on notches and/or protrusions.

Force is applied to the extendable archwire which extends the extendablearchwire by applying force to the archwire to move the adjustmentportion including the locking surfaces distally with respect to theanchor. The anchor may be a band, ligature or bracket or other suitableattachment point including another counteracting ratchet bracket. Asforce is applied to the extendable archwire, tension results in thearchwire as the loop spring activates. Depending on the type of loopspring used, “opening” may not be the correct word for describing theaction of the spring. Orthodontists typically describe the action of thespring as “activating” the spring rather than “opening” of the spring.Activating may include opening or closing a loop or imparting a load toa spring device. For instance, if a coil spring is used, the springwould not be opened “per se” but rather it would be unwound against thespring force. The pawl interengages respective ones of the lockingsurfaces as the adjustment portion is forced through the passageway ofthe bracket.

The archwire and pawl form a ratchet and secure the archwire wherein thepawl interengages a respective desired one of the locking surfaces andprevents the loop spring from retracting the adjustment portion of theextendable archwire toward the anchor.

The archwire may be constructed from a metal, metal alloy, or non-metalmaterial and may have a plurality of shapes and dimensions so as tomaximize its effectiveness and the effectiveness of the pawl.

The archwire of the instant invention encompasses use of Nickel-Titaniumalloys. These materials are resilient in character meaning that theyconsiderable flexibility which aids in the treatment of a patient.However, formation of a loop-spring (either open or closed) by atreating orthodontist is difficult because of their resiliency. However,when manufactured loop-springs and indicia may be created and loadcurves developed. These alloys are very popular in orthodontic practice.

It is an object of the present invention to provide an archwire with aloop spring wherein the loop may be open, closed, and may assume otherconfigurations.

It is an object of the present invention to provide a bracket or tubehaving an aperture which communicates with a passageway through thebracket.

It is an object of the present invention to provide a bracket with apawl affixed thereto and an archwire having locking surfaces thereininserted through the bracket such that a ratchet is formed whichprohibits retraction of the archwire.

It is an object of the present invention to provide an archwire withreference markings, engravings, or other indicia on the archwire inproximity to a loop spring to measure distances between the marks uponthe application of force to open (activate) the loop springs for thepurpose of calculating force applied. While the markings, engravings orother indicia are preferred to be in proximity to the loop spring it isspecifically contemplated that they may be located remotely from theloop spring or anywhere along the surface of the archwire conducive tothe object measurement.

It is an object of the present invention to provide an archwire withlocking surfaces in notches and/or protrusions which coact with a pawlto provide proper tension to the teeth of a patient.

It is an object of the present invention to provide a method of applyinga desired force to a tooth or teeth of a patient.

It is an object of the present invention to generate a force-extensioncurve (load curve) for an archwire.

It is an object of the present invention to generate a force-extensioncurve (load curve) for a plurality of archwires having differentgeometries made from a variety of materials.

It is an object of the present invention to use indicia which are notnecessarily visible to the human eye but which may be identified andmeasured magnetically or by some other method.

It is an object of the present invention to disengage the pawl from thearchwire enabling easy insertion or extraction of the archwiretherefrom.

It is an object of the present invention to provide a sheath or someother disengaging apparatus over a portion of the pawl so as to preventengagement of the pawl with archwire.

It is an object of the present invention to provide a bracket and pawldevice which includes a groove in either the pawl or the bracket forinserting a tool for lifting the pawl and allowing the retraction of thepawl so as to release the wire.

It is an object of the present invention to provide a bracket whichlocks and unlocks an archwire.

These and other objects of the invention will be best understood whenreference is made to the Brief Description of the Drawings and theDescription of the Invention which follows hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example of an extendable archwirewith unloaded open-loop springs, calibration marks (indicia) located inproximity to the open-loop springs, and adjustment portions of thearchwire near the ends of the archwire having notches therein.

FIG. 1A is another perspective view of the extendable archwire asillustrated in FIG. 1.

FIG. 1B is a perspective view of an example of an extendable archwirewith unloaded open-loop springs, calibration marks (indicia) located inproximity to the open-loop springs, and adjustment portions of thearchwire near the ends of the archwire having protrusions thereon.

FIG. 1C is another perspective view of the extendable archwire asillustrated in FIG. 1B.

FIG. 1D is a perspective view of an example of an extendable archwirewith unloaded offset-loop springs, calibration marks (indicia) locatedin proximity to the offset-loop springs, and adjustment portions of thearchwire near the ends of the archwire having notches therein.

FIG. 1E is another perspective view of the extendable archwire asillustrated in FIG. 1D.

FIG. 1F is a view taken along the lines 1F-1F of FIG. 1D.

FIG. 1G is a perspective view of an example of an extendable archwirewith unloaded offset-loop springs, calibration marks (indicia) locatedin proximity to the offset-loop springs, and adjustment portions of thearchwire near the ends of the archwire having protrusions thereon.

FIG. 1H is another perspective view of the extendable archwire asillustrated in FIG. 1G.

FIG. 2 is an enlarged portion of the extendable archwire of FIG. 1illustrating one of the unloaded open-loop springs, with somewhatdifferent calibration marks (indicia) located in proximity to theopen-loop spring, and adjustment portions of the archwire near the endsof the archwire having notches therein.

FIG. 2A is an enlarged portion of the extendable archwire similar toFIG. 2 in the loaded state.

FIG. 2B is a perspective view of FIG. 2A.

FIG. 2C is a perspective view of a portion of FIG. 1B illustrating oneof the loaded open-loop springs, calibration marks (indicia) located inproximity to the open-loop spring, and an adjustment portion of thearchwire near the end of the archwire having protrusions thereon.

FIG. 2D is an example of a loop in the form of a coil spring.

FIG. 2E is an example of a loop wherein one leg includes a loop therein.

FIG. 2F is an example of a loop flattened on the bottom thereof.

FIG. 2G is an example of a loop wherein the legs are spaced apart.

FIG. 2H is an enlargement of a portion of FIG. 2 illustrating one of thenotches in the adjustment portion of the extended archwire.

FIG. 2I is an enlargement of a portion of FIG. 2C illustrating one ofthe protrusions in the adjustment portion of the extended archwire.

FIG. 2J is a view similar to FIG. 2I illustrating an archwire having aland or space between protrusions in the adjustment portion of differentlength as compared to FIG. 2I.

FIG. 2K is an enlargement of a portion of FIG. 2B illustrating one ofthe notches in the adjustment portion of the extended archwire.

FIG. 2L is a view similar to FIG. 2K illustrating an archwire having aland or space between notches in the adjustment portion of differentlength as compared to FIG. 2K.

FIG. 3 is a side view of an extendable archwire wherein the archwire isadapted for use with a band, bracket or ligature, with an unloadedopen-loop spring, calibration marks (indicia) located in proximity tothe open-loop spring, and an adjustment portion of the archwire near theend of the archwire having notches therein.

FIG. 3A is a side view of an extendable archwire similar to FIG. 3 witha load applied.

FIG. 3B is a perspective view of the extendable archwire of FIG. 3A.

FIG. 3C is a perspective view similar to FIG. 3B wherein protrusions areused on the extendable archwire.

FIG. 4 is a partial cross-sectional view of an orthodontic molar bracketillustrating an aperture in the occlusal portion, a pawl affixed to thebracket, and an extendable archwire having protrusions thereon insertedthrough the bracket.

FIG. 4A is partial cross-sectional view of an orthodontic molar bracketsimilar to FIG. 4 with the stop surface of the pawl engaging the lockingsurface of a protrusion.

FIG. 4B is a partial cross-sectional view of an orthodontic molarbracket illustrating an aperture in the occlusal portion, a pawl affixedto the bracket, and an extendable archwire having notches thereininserted through the bracket.

FIG. 4C is partial cross-sectional view of an orthodontic molar bracketsimilar to FIG. 4 with the stop surface of the pawl engaging the lockingsurface of a notch in the extendable archwire.

FIG. 4D is a partial cross-sectional view of an orthodontic molarbracket wherein the pawl is affixed to the bracket and extends beyondthe body of the bracket with the stop surface of the pawl engaging thelocking surface of a protrusion.

FIG. 4E is a partial cross-sectional view of an orthodontic molarbracket illustrating an aperture in the occlusal portion, a pawl affixedto the bracket and having a sheath over a portion of the pawl, and anextendable archwire having notches therein inserted through the bracket.

FIG. 4F is a view of an orthodontic molar bracket including the pawlwith an extendable archwire therethrough.

FIG. 4G is a view of another orthodontic molar bracket including theaperture for receiving the pawl.

FIG. 4H is a side view of the orthodontic molar bracket illustrating apassageway therethrough.

FIG. 4I is an exploded assembly view illustrating a molar bracket, pawland extendable archwire.

FIG. 4J is an assembly view illustrating a pawl having a curved ramp.

FIG. 4K is a partial cross-sectional view of an orthodontic molarbracket illustrating an aperture in the occlusal portion, a pawl affixedto the bracket using a ligation device (elastomeric, steel . . . etc.),and an extendable archwire having protrusions thereon inserted throughthe bracket.

FIG. 4L is partial cross-sectional view of an orthodontic molar bracketsimilar to FIG. 4 with the stop surface of the pawl engaging the lockingsurface of a protrusion.

FIG. 4M is a view of an orthodontic molar bracket similar to FIG. 4Fincluding the pawl having slots therein secured to the bracket by morethan one ligation or varying patterns of a single ligation device.

FIG. 5 is an orthographic projection of the orthodontic device appliedto a patient's teeth with load applied and the loop-springs activated.

FIG. 5A is an orthographic projection of the orthodontic device appliedto a patient's teeth with no load applied and the loop-springsdeactivated.

FIG. 5B is an enlargement of a bracket applied to a tooth.

FIG. 5C is an enlargement of a bracket applied to a tooth with a sheathover a portion of the pawl.

FIG. 6 is a perspective view of the orthodontic device applied to teethwith load applied and the loops-springs activated.

FIG. 7 is a block diagram of a treatment process.

The drawings will be better understood when reference is made to theDescription of the Invention and Claims which follow hereinbelow.

DESCRIPTION OF THE INVENTION

In referring to the drawings hereinbelow the application of a load isdescribed herein without always indicating that a load is applied orshowing structure necessary to create the load.

FIG. 1 is a perspective view 100 of an example of an extendable archwire(103, 104, 161, 190) with unloaded open-loop springs 101, 102,calibration marks (indicia) (170, 170A, 170B, 171, 171A, 171B) locatedin proximity to the open-loop springs, and adjustment portions 120A,121A of the archwire near the ends 120, 121 of the archwire havingnotches 105 therein. The first open-loop spring 101 has legs 111, 112and an intermediate portion 113. Bends 131, 132 in the archwire form thedesired loop-spring shape with gap 180 between the legs of the spring.

Second open-loop spring 102 has legs 114, 115 and an intermediateportion 116. Bends 134, 135 in the archwire form the desired loop-springshape with gap 181 between the legs of the spring.

Deformation of the archwire forms a spring which has a spring constantor spring factor determined as disclosed hereinbelow.

First leg 111 is sometimes referred to herein as the posterior leg offirst loop spring 101 and second leg 112 is sometimes referred to hereinas the anterior leg 112 of the first loop spring 101. Second leg 114 issometimes referred to herein as the anterior leg of second open-loopspring 102 and first leg 115 is sometimes referred to herein as theposterior leg of the second open-loop spring 102.

Spaces 107 between notches 105 in the adjustment portions 120A, 121A ofthe archwire are viewed in FIG. 1. The archwire is sometimes referred toas the extendable archwire herein because the ends 120, 121 of thearchwire may be extended through a molar bracket under force opening thesprings 101, 102. Although two springs 101, 102 are illustrated in FIG.1 this invention specifically contemplates the use of one spring or morethan two springs.

The archwire material may be stainless steel, nickel titanium, othermetal composition or any other material which may form an archwire andit may have various cross-sectional shapes. Loops spring characteristicsas desired may be formed in the archwire. Orthodontists may form theloops or they may be formed by the original equipment manufacturer. Theinvention disclosed herein will enable the orthodontist or the originalequipment manufacturer to determine a force-extension curve forarchwires having specific spring configurations. The orthodontist maythen calculate the force that has been applied to a tooth or to a groupof teeth knowing the deflection of the spring upon activation. Theequation used to calculate the force may be determined by the supplierof the archwire or it may be determined by the orthodontist.

For instance, the original equipment manufacturer may use a tensionmeter or other device to measure an applied force by securing one end ofan archwire to an immovable anchor and then applying force to thearchwire in a direction opposite the anchor and recording the amount offorce applied. Simultaneously, the deflection or opening of the springis recorded by measuring the distance between marks 170, 171 which areinscribed or marked on the archwire about the loops 101, 102. First aninitial distance is determined for the unloaded condition. Next, thedistance is recorded which corresponds to the force applied to thearchwire. In this way a force-deflection curve is generated whichenables the orthodontist to know precisely the tension in the loopallowing force applied to the teeth to be estimated with correspondingprecision.

FIG. 1A is another perspective view 100A of the extendable archwire asillustrated in FIG. 1. Gaps 180, 181 of loop springs 101, 102 areillustrated well in FIG. 1A. Occlusal side 162 of the archwire is alsoshown in FIG. 1A and notches 105 are viewed in the archwire as well. Byocclusal it is meant to denote the grinding side of the teeth. Notches105 or protrusions 106 as viewed in other drawings are preferablylocated on the occlusal side of the archwire so that the orthodontistmay access the brackets and adjust the tension (force) in the archwire.For instance, the notches or protrusions may be located on the buccal,gingival, or lingual sides.

FIG. 1B is a perspective view 100B of an example of an extendablearchwire with unloaded open-loop springs 101, 102, calibration marks(indicia) (170, 170A, 170B, 171, 171A, 171B) located in proximity to theopen-loop springs, and adjustment portions 120A, 121A of the archwirenear the ends of the archwire having protrusions 106, 106A thereon. Theadjustment portions 120A, 121A are generally indicated in the drawingfigures, however, it is specifically contemplated that the adjustmentportions may include a larger portion of the archwire if more lockingsurfaces or more or different spacing of the locking surfaces are neededor desired. FIG. 1C is another perspective view 100C of the extendablearchwire as illustrated in FIG. 1B wherein the protrusions 106, 106A arebest illustrated. Space 108 between the protrusions of the adjustmentportion of the archwire are also viewed well in FIG. 1C.

FIG. 1D is a perspective view 100D of an example of an extendablearchwire with unloaded offset-loop springs 101D, 102D, calibration marks(indicia) 178, 179 located in proximity to the offset-loop springs, andadjustment portions 120A, 121A of the archwire near the ends of thearchwire having notches 105 therein. The offset-loop springs 101D, 102Dare sometimes referred to herein as closed-loop springs.

Offset-loop spring 101D includes legs 111D, 112D and intermediatejoining portion 113D which joins the legs. Offset-loop 101D includesbending portions 131A, 132A. The legs 111D, 112D are offset and have agap 141 therebetween.

Offset-loop spring 102D includes legs 114D, 115D and intermediatejoining portion 116D which joins the legs. Offset-loop 102D includesbending portions 133A, 134A. The legs 114D, 115D are offset and includea gap 142 therebetween. FIG. 1F is a view 100F taken along the lines1F-1F of FIG. 1D and illustrates gap 142, legs 114D, 115D, and joiningportion 116D.

FIG. 1E is another perspective view 100E of the extendable archwire withclosed-loops 101D, 102D as illustrated in FIG. 1D. FIG. 1G is aperspective view 100G of an example of an extendable archwire withunloaded offset-loop springs 110D, 102D, calibration marks 178, 179(indicia) located in proximity to the offset-loop springs, andadjustment portions of the archwire near the ends of the archwire havingprotrusions 106, 106A thereon. FIG. 1H is another perspective view ofthe extendable archwire as illustrated in FIG. 1G.

FIG. 2 is an enlarged portion 200 of the extendable archwire of FIG. 1illustrating one of the unloaded open-loop springs 102, calibrationmarks (indicia) 170, 171 located in proximity to the open-loop spring,and adjustment portions 121A of the archwire near the end 121 of thearchwire having notches 105 therein. Reference numeral 210 represents adiscontinuity or break in the archwire so that better resolution in thedrawing may be achieved.

FIG. 2H is an enlargement of a portion 200H of FIG. 2 illustrating oneof the notches 105 in the adjustment portion of the extended archwire.Notch 105 includes a ramp 105A and a stop face 105B.

Still referring to FIG. 2, reference numeral 203 is the distance betweenthe marks with no load on the archwire. Reference numeral 204 is thedistance between the stop faces 105B of the notches. Depth of thenotches is indicated by reference numeral 206 and the length of thenotch is represented by reference numeral 205.

Different geometry of the notches and their spacing 204 may be used asdesired by the orthodontist. For instance, if the notches 105 and theirstop faces 105B are spaced closer together then the adjustment of theforce associated with each notch is incrementally smaller from notch tonotch. This allows the orthodontist to achieve greater control of theforce applied to a patient's tooth or teeth. In other words differentarchwires may be supplied with different notch spacings and withdifferent loop springs providing the orthodontist with a structure andmethod for better treating a patient. Additionally, the notch depth 206may be adjusted so as to ensure a larger or more pronounced stop face105B in the circumstance where a particularly large force is applied toa patient's tooth or teeth. Reference numeral 207 represents thethickness of the archwire in one direction. The archwire may assume anycross-sectional profile and may be round, square, rectangular,triangular or any other polygonal cross-sectional shape. In thesituation of the round wire then the notch or protrusion will extendaround the circumference of the wire.

The load curves (force-extension curves) which are described herein willbe primarily determined by archwire manufacturers. Use of the loadcurves in conjunction with clinical data will enable more effectivetreatment of a patient.

FIG. 2D is an example 200D of a loop spring in the form of a coilspring. Indicia 201, 202 is inscribed or painted on the archwire inproximity to the coil spring legs 214D, 215D. Joining portion 216D is acoil which joins the legs 214D, 215D. Reference numeral 203D representsthe distance between the legs without the application of force to thearchwire.

FIG. 2E is an example 200E of a loop spring wherein one leg includes aloop 217E therein. Legs 214E, 215E and joining portion 216E are allshown in FIG. 2E are marks 201, 202 separated by distance 203E in anunloaded state.

FIG. 2F is an example 200F of a loop spring with an intermediate portion216F flattened on the bottom thereof. Legs 214F, 215F include portions218F, 219F which together with joining portion 216F form a generallyt-shaped loop spring. Marks 201, 202 are separated by distance 203F inthe unloaded state.

FIG. 2G is an example 200G of a loop spring wherein the legs 214G, 215Gare joined by intermediate portion 216G and marks 201, 202 are spacedapart by the distance 203G. Those skilled in the art upon reading thedisclosure herein will readily recognize that loops having variousshapes may be employed in the archwire without departing from the spiritand scope of the claims as set forth herein.

FIG. 2A is an enlarged portion 200A of the extendable archwire similarto FIG. 2 in the loaded state illustrating the distance between marks203A. FIG. 2B is an enlarged portion 200B of the extendable archwiresimilar to FIG. 2 in the loaded state illustrating the distance betweenmarks 203A and the notches 105 and their stop faces 105B.

FIG. 2C is a perspective view 200C illustrating a loaded open-loopspring 102, calibration marks (indicia) 170, 171 located in proximity tothe open-loop spring with a distance 203A therebetween, and anadjustment portion of the archwire near the end of the archwire havingprotrusions 106, 106A thereon. FIG. 2I is an enlargement 200I of aportion of FIG. 2C illustrating one of the protrusions 106, 106A in theadjustment portion of the extended archwire. Ramp 106A terminates instop face 106 of the protrusion. Space 108 which of nominal archwiredimension separates the ramp 106A and the stop face 106B of the adjacentprotrusion. FIG. 2J is a view 200J similar to FIG. 2I illustrating anarchwire having a land or space 108A between protrusions 106, 106A inthe adjustment portion 121A of different length as compared to FIG. 21.When the protrusions are closer together as illustrated in FIG. 2J thenthe force applied can be adjusted with greater precision as is done whenmaking a vernier (fine) adjustment to an instrument.

FIG. 2K is an enlargement 200K of a portion of FIG. 2B illustrating oneof the notches 105 in the adjustment portion 121A of the extendedarchwire. FIG. 2L is a view 200L similar to FIG. 2K illustrating anarchwire having a land or space 107A between protrusions in theadjustment portion 121A of different length as compared to FIG. 2K. Whenthe notches 105 are closer together as illustrated in FIG. 2L then theforce applied can be adjusted with greater precision as is done whenmaking a vernier (fine) adjustment to an instrument. In other words theadjustment made in FIG. 2K is somewhat more of a coarse adjustment ascompared to the adjustment in FIG. 2L.

FIG. 3 is a side view 300 of an extendable archwire wherein the archwireincludes a loop 301 is adapted for use with a band, bracket or ligature,with an unloaded open-loop spring 102, calibration marks (indicia) 170,171 located in proximity to the open-loop spring, and an adjustmentportion of the archwire near the end of the archwire having notchestherein. FIG. 3B is a perspective view 300B of the extendable archwire190 of FIG. 3. FIG. 3C is a perspective view 300C similar to FIG. 3Bwherein protrusions 106, 106A are used on the extendable archwire and aload is applied.

FIG. 3A is a side view 300A of an extendable archwire similar to FIG. 3with a load applied as indicated by the open loop spring 102 and theindicia 170, 171 and the distance 203A between the indicia.

FIG. 4 is a partial cross-sectional view 400 of an orthodontic molarbracket 405 illustrating an aperture 410 in the occlusal portion orupper portion 406 of the body 405A of the bracket 405. A loop spring 501such as that shown in FIG. 5A urges the archwire 190 rightwardly whenforce is applied to the archwire 190 to move it leftwardly. Pawl 403 isaffixed to the bracket 405 and an extendable archwire having protrusions106, 106A thereon is inserted through a passageway 408 of the bracket.Pawl 403 includes a cam 404 and a stop surface 403A.

Referring to FIGS. 4 and 4F, pawl 403 includes an arm 401 which isaffixed 401A by welding, soldering, ligation or adhesive to the uppersurface 421 of the bracket 405.

Extension arm 402 of the pawl extends past the aperture 410 in the upperportion 406 of the body 405A of the bracket. FIG. 4 illustrates the pawl403 engaging ramp 106A of the protrusion. In this condition a force (notshown) is urging the archwire leftwardly. This force is created by theorthodontist by pushing or pulling the archwire 190 through the lumen orpassageway 408. In the condition as illustrated in FIG. 4 the archwire190 is not locked and may move rightwardly upon the discontinuation offorce until pawl stop surface 403A engages the locking surface 106 onthe next adjacent protrusion.

Still referring to FIG. 4, the pawl cam surface 404 and the apex of thepawl cam surface 404 and the pawl stop surface 403A interengage theocclusal side 162 of the archwire and, in particular, the adjustmentportion 120A of the archwire which includes the protrusion lockingsurface 106, protrusion ramp surface 106A and the space 108 between theramp and locking surfaces. It will be noted that one geometry of the camsurface 403A has been shown by way of example. However, it isspecifically contemplated that other cam geometry can be used. Forinstance a non-linear pawl cam geometry may be used.

FIG. 4A is partial cross-sectional view 400A of an orthodontic molarbracket 405 similar to FIG. 4 with the pawl stop surface 403A engagingthe locking surface 106 of a protrusion. In this condition the archwireis free to move leftwardly under force against the loop spring (notshown) but the archwire 190 may not move rightwardly.

FIG. 4B is a partial cross-sectional view 400B of an orthodontic molarbracket 405 illustrating an aperture 410 in the occlusal portion, a pawlaffixed to the bracket, and an extendable archwire having notches 105therein inserted through the bracket. FIG. 4B is similar to FIGS. 4 and4A except that the archwire 190 includes an adjustment portion havingnotches 105. As shown in FIG. 4B, the apex of the pawl 403 engages theocclusal side 162 of the archwire 190. The archwire 190 is free to moverightwardly upon the discontinuation of force to urge the archwireleftwardly.

Depending on the length of the archwire 190 and of the adjustmentportion, the adjustment portion 120A may be inserted into the lumen 408and reside there without the application of force by orthodontist andwithout the application of force by the loop spring. This condition orstate just described is also applicable to FIGS. 4, 4A, and 4C.

Referring to FIGS. 4 and 4B, pawl arm 401 will bend as the apex of thepawl rides along the occlusal side 162 of the adjustment portion of thearchwire 190. Arm 401 can be made of variety of materials includingstainless steel or plastics and has sufficient flexibility andresilience to follow the contour of the archwire and to lock the pawlstop surface 403A against the looking surfaces 105B and 106. Other metalalloys or non-metallic materials may be used.

Still referring to FIGS. 4 and 4A, reference numeral 470 represents anotch in pawl 403 into which a tool may be inserted to allow the raisingof the pawl so as to retract the archwire from the bracket.Alternatively, reference numeral 471 represents a notch in body 406 intowhich a tool may be inserted to allow the raising of the pawl.

FIG. 4C is partial cross-sectional view 400C of an orthodontic molarbracket similar to FIG. 4 with the stop surface of the pawl 403Aengaging the locking surface 105B of a notch 105 in the extendablearchwire. FIG. 4C is similar to FIG. 4A in operation and effect. Namely,archwire 190 may be forcefully urged leftwardly against the spring 501(not shown).

FIG. 4D is a partial cross-sectional view 400D of an orthodontic molarbracket wherein the pawl 403 is affixed to the bracket and extendsbeyond the end 409 of the upper portion 406 of the body of the bracketwith the stop surface of the pawl 403A engaging the locking surface 106of a protrusion. The example of FIG. 4D offers access to theorthodontist of the extension arm 402 for releasing the archwire fromthe bracket. It will be noticed when reference is made to FIG. 4D thatthe pawl 403 is attached to the upper portion of the body 406 aconsiderably longer distance than that illustrated in FIGS. 4A-C andthus the amount of bending of the pawl arm 401 is reduced.

FIG. 4E is a partial cross-sectional view 400E of an orthodontic molarbracket 405 illustrating an aperture in the occlusal portion of theupper body 406 of the bracket 405A. A pawl 403 is affixed to the bracketand a sheath 407 resides over a portion of the pawl. As in the examplesof FIGS. 4-4D, an extendable archwire 190 having notches therein hasbeen inserted through the bracket.

FIG. 4F is a view 400F of an orthodontic molar bracket 455 including thepawl with an extendable archwire therethrough from the occlusal (chewingside) of the teeth when reference is made to FIGS. 5 and 5A. Arm 422 isillustrated in FIG. 4F and is used to connect other orthodonticstructures thereto. Base 454 is affixed to the tooth of a patient or toan orthodontic band and a flange or transitional portion 420interconnects the base with the molar bracket. The occlusal side 162 ofthe archwire 190 is viewed in FIG. 4F along with notches 105.

FIG. 4G is a view 400G of orthodontic molar bracket 405 with the pawl403 removed therefrom illustrating the aperture 410 for receiving thepawl 403. Aperture 410 is illustrated as being rectangular but it isenvisioned that it could be in any cross-sectional shape and that thecross-sectional shape could vary. As shown in FIG. 4G, aperture 410communicates with passageway 408 and is arranged orthogonally withrespect thereto. Alternate orientations of the pawl and the aperture arespecifically contemplated. In other words, the pawl and the aperture maybe oriented on the buccal side or the gingival side. FIG. 4H is a sideview 400H of the orthodontic molar bracket 405 illustrating thepassageway 408 therethrough and the arm 422.

FIG. 41 is an exploded assembly view 400G illustrating a molar bracket405, pawl 403 and extendable archwire 190.

FIG. 4J is a view 400J illustrating a pawl 404A having a curved camsurface 404A. FIG. 4K is a partial cross-sectional view 400K of anorthodontic molar bracket 405 illustrating an aperture 410 in theocclusal portion, a pawl 403 affixed to the bracket using an elastomericor metal ligature 485, and an extendable archwire having protrusions106, 106A thereon inserted through the bracket. Slots or passageways401B enable the ligation device to be inserted through the slot suchthat the ligation device resides partially under the pawl. Pawl 403 isable to pivot and to follow the contour of the archwire as it isalternately raised and lowered as the archwire is moved (extended)leftwardly when viewing FIGS. 4K and 4L.

FIG. 4L is partial cross-sectional view 400L of an orthodontic molarbracket similar to FIG. 4 with the stop surface 403A of the pawl 403engaging the locking surface 106 of a protrusion. In FIG. 4L, theelastomeric device secures the pawl against the locking surface of thearchwire.

FIG. 4M is a view 400M of an orthodontic molar bracket 455 similar toFIG. 4F including the pawl having slots 401B therein secured to thebracket 455 by an elastomeric or metal ligature device 485. Slot 401Bterminates in port 401C having a diameter which is sufficiently largerthan the elastomeric or metal ligature devices 485. The elastomeric ormetal ligature device 485 is pressed into and through the slot 401B.

FIG. 5 is an orthographic projection 500 of the orthodontic deviceapplied to the teeth 450, 452 of a patient with load applied and theloop-springs activated with a distance 203A therebetween. Theorthodontic device includes the archwire and brackets as described inthis specification. Intermediate brackets 465 guide the archwire andprovide support thereto. Molar brackets 455 and 405 are illustrated inFIG. 5 along with archwires for the upper and lower teeth of thepatient.

Use of the device includes anchoring one end of the archwire in thefirst instance. The anchor may be a molar or other bracket or anotherdental appliance such as a band or a wire. The adjustment end of thearchwire is inserted into the passageway in the molar bracket. As thearchwire is inserted into the passageway it overcomes the pawl liftingthe pawl as necessary. Pawl 403 extends into the passageway or lumen 408as viewed in FIGS. 4A and 4C.

Alternatively, if sheath 407 is used over the pawl extension 402, thenpawl 403 is prohibited from entering the passageway 408 thus makinginsertion and retraction of the archwire easier. If pawl sheath 407 isused it will provide a seamless transition for orthodontists familiarwith the prior art method of inserting the archwire into and through thepassageway of the molar bracket.

The molar bracket used for adjustment of the archwire is, of course,first secured to a molar. There may be one or more intermediate guidedevices such as brackets 465, 590 which guide and secure (anchor) thearchwire and maintain its stability. For instance, the anchor may be inthe form of a ligation to a bracket or brackets affixed to a tooth orteeth such as those shown in FIGS. 5 and 5A. These brackets mayself-ligating brackets or the ligature may be affixed by theorthodontist. Further, another example of an anchor may be a molarbracket located on the other end of the archwire where it may engage abracket such as that disclosed by the instant invention or aconventional bracket.

Once the archwire is inserted into a lumen or passageway of the molarbracket 405, 455, the orthodontist must ensure that the sheath 407 (ifused) is removed if so desired to activate the loop. Then, theorthodontist forcefully pushes or pulls the archwire further through themolar bracket and while this is happening the pawl 403 rides along(i.e., follows) the contour of the occlusal side 162 of the adjustmentportion 120A. The contour of the occlusal side 162 is either notched 105or has protrusions 106, 106A as described above. As the orthodontistpushes or pulls the archwire further through the molar bracket, tensionin the archwire increases as the spring loop is activated (deflected oropened). As the spring is activated (deflected), indicia (markings,engravings, embedded materials) spaced on the archwire located on eitherside of the spring move. In some instances such as those depicted, forexample, in FIGS. 1-1C the indicia will move further apart uponactivation of the open-loop spring 101, 102. In FIGS. 1D-1H, the indiciawill move closer together upon activation of the closed-loop spring101D, 102D. Distance measurements are then made by the orthodontist.Rulers, compasses, optical measuring devices or other devices (used todetect reference points either in the visible spectrum or not determinethe distance between the marks.) Optical measuring devices may employmultiple indicia in determining the deflection distance (i.e., thedistance between reference indicia).

Once the distance between the markings on the archwire is measured, thetreating orthodontist is able to correlate the force (tension) appliedto the teeth using the load curves (which plot force versus distancebetween the marks, i.e., activation opening of the spring) or anequation relating force to the distance between the markings for thespecific archwire and spring being used. Force is defined as mass timesacceleration. Force is expressed in Newtons (symbol N) which isequivalent to kg-m/s². Newtons divided by 0.0098066 equalsgrams-force.Typically, orthodontists express force as grams-force or Newtons.

FIG. 5A is an orthographic view 500A of the orthodontic device appliedto the teeth 450, 452 of a patient with no load applied and theloop-springs deactivated. In FIG. 5A the archwire is secured to brackets405, 455. The indicia (markings) on the archwire indicate that the loopsare in their unloaded state. The archwire will be ligated or otherwisesecured to brackets 465. Reference numerals 180, 181, 580, 581 representthe contact points between the respective open-loop springs.

The condition illustrated in FIG. 5 may be observed during initialapplication and treatment of the patient. It should be noted that duringthe treatment of a patient the orthodontist will review progress of theorthodontic device by periodically measuring the change in distancebetween the indicia or the rate of change of the distance between theindicia.

Readjustment of the tension during treatment of a patient may benecessary to increase or reduce the tension in the archwire. If tensionis reduced the orthodontist will disengage the pawl extension arm 402and urge the archwire in the anterior direction. Alternatively, theorthodontist may place the sheath over the pawl extension arm 402.

FIG. 5B is an enlargement 500B of a molar bracket 455 applied to atooth. Reference is made to FIG. 5 to identify and bracket 455. Pawl arm401 and extension arm 402 are illustrated in FIG. 5B as located on theocclusal (grinding) side of the teeth as this gives the orthodontistgreater access to the extension arm. If the example of FIG. 4D or 4E areused then access to the pawl extension arm is increased and theseexamples may facilitate initial treatment or readjustment of thearchwire. FIG. 5C is an enlargement 500C of a bracket 455 applied to atooth with the sheath 407 over a portion of the pawl extension arm 402.As illustrated in FIGS. 5C and 4E, the pawl does not engage theadjustment portion of the archwire.

FIG. 6 is a perspective view 600 of the orthodontic device applied toteeth with load applied and the loops-springs 101, 102, 501, 502activated.

FIG. 7 is a block diagram 700 of an example of a process for thetreatment of a patient comprising the steps of attaching a bracket to atooth 701, inserting an adjustment portion of the archwire into andthrough the passageway of the bracket 702, attaching one end of anarchwire having a loop to an anchor 703, extending the extendablearchwire by applying force to the archwire to move the adjustmentportion including locking surfaces distally with respect to the anchor704, tensioning the archwire by activating the loop spring 705,interengaging the pawl and locking surfaces 706, and ratcheting andsecuring the archwire when the pawl interengages the desired lockingsurface of the archwire 707.

A list of reference numerals to aid the reader follows.

REFERENCE NUMERALS

-   100 . . . perspective view of archwire with open-loop springs,    notches, and marks-   100A—perspective view of archwire with open-loop springs, notches in    the adjustment portion and marks-   100B—perspective view of archwire with open-loop springs,    protrusions on the adjustment portion and marks-   100C—perspective view of archwire with open-loop springs,    protrusions on the adjustment portion and marks-   100D—perspective view of archwire with closed-loop springs, notches    in the adjustment portion and marks-   100E—perspective view of archwire with closed-loop springs, notches    in the adjustment portion and marks-   100F—view of closed loop-   100G—perspective view of archwire with closed-loop springs,    protrusions in the adjustment portion and marks-   100H—perspective view of archwire with closed-loop springs,    protrusions in the adjustment portion and marks-   101—first open-loop spring-   101D—first closed-loop spring-   102—second open-loop spring-   102D—second closed-loop spring-   103—labial (near lips)/buccal (near cheeks) side of archwire-   104—lingual (near tongue) side of archwire-   105—notch-   105A—ramp of notch-   105B—stop face of notch-   106—stop face of protrusion-   106A—ramp on protrusion-   107—land portion of archwire between notches-   107A—land portion of archwire between notches-   108—land portion of archwire between protrusions-   108A—land portion of archwire between protrusions-   111—first leg (posterior leg) of first loop spring-   111D, 112D, 114D, 115D—leg of closed loop spring-   112—second leg (anterior leg) of first loop spring-   113—intermediate portion of first open-loop spring-   113D—intermediate portion of first closed-loop spring-   114—second leg (anterior leg) of second open-loop spring-   115—first leg (posterior leg) of second open-loop spring-   116—intermediate portion of second open-loop spring-   116D—intermediate portion of second closed-loop spring-   120—first end of archwire-   120A, 121A—adjustment portion of archwire-   121—second end of archwire-   131—first bend of first leg of first loop spring-   131A, 132A—bend of first closed-loop spring-   132—second bend of second leg of first loop spring-   133A, 134A—bend of second-closed-loop spring-   134—third bend of second leg of second loop spring-   135—fourth bend of second leg of second loop spring-   141, 142—gap between legs of closed loop spring-   161—gum (gingival) side of archwire-   162—occlusal (grinding side of teeth) side of archwire-   170, 170A, 170B, 171, 171A, 171B, 178, 179, 201, 202—marks/indicia    on archwire-   180—unloaded gap between legs of first loop-   181—unloaded gap between legs of second loop-   190—archwire-   200—view of a portion of the archwire, open-loop and notches with no    load applied to archwire-   200A—view of a portion of the archwire, open-loop and notches with a    load applied to the archwire-   200B—perspective view of a portion of the archwire, open-loop and    notches with a load applied to the archwire-   200C—perspective view of a portion of the archwire, open-loop and    notches with a load applied to the archwire-   200D, 200E, 200F, 200G—perspective view of exemplary loop-   200H—enlarged portion of archwire and notch-   200I—enlarged portion of archwire and protrusion-   200J—illustration of protrusions closer together-   200K—enlarged portion of archwire and notch-   200L—illustration of notches closer together-   203—distance between marks with no load on the archwire-   203A—distance between marks with load applied to the archwire-   203D, 203E, 203F, 203G—distance between marks-   204—distance between stop faces of notches-   205—width of notch-   206—depth of notch-   207—thickness of archwire in one direction-   210—archwire drawing break-   214D, 214E, 214F, 214G, 215D, 215E, 215F, 215G,—loop-legs-   216D, 216E, 216F, 216G—intermediate portion of loops-   217F, 218F, 219F—loops-   300—view of an exemplary archwire with notches in the adjustment    portion and no load applied to the archwire-   300A—view of an exemplary archwire with load applied to the archwire-   300B—perspective view of an exemplary archwire with load applied to    the archwire-   300C—perspective view of an exemplary archwire with protrusions in    the adjustment portion and a load applied to the archwire-   301—loop at end of archwire-   321—end of loop-   400—cross-sectional view of orthodontic molar bracket, pawl and    archwire with protrusions on the adjustment portion in an unlocked    position-   400A—cross-sectional view of orthodontic molar bracket, pawl and    archwire with protrusions on the adjustment portion in locked    position-   400B—cross-sectional view of orthodontic molar bracket, pawl and    archwire with notches in the adjustment portion in an unlocked    position-   400C—cross-sectional view of orthodontic molar bracket, pawl and    archwire with notches in the adjustment portion in locked position;-   400D—cross-sectional view of orthodontic molar bracket, pawl and    archwire with protrusion on the adjustment portion in locked    position-   400E—cross-sectional view of orthodontic molar bracket, pawl, pawl    sheath and archwire with notches in the adjustment portion in    unlocked position-   400F—bottom view of orthodontic molar bracket 455-   400G—top view of orthodontic molar bracket 405 with pawl removed-   400H—distal end view of orthodontic molar bracket 405-   400I—exploded front view of orthodontic molar bracket 405, pawl, and    adjustment portion of archwire-   400J—pawl with curved cam surface-   400K—cross-section of bracket with elastomeric securement of pawl-   400L—cross-section of bracket with elastomeric securement of pawl to    prevent retraction of archwire-   400M—example of elastomeric device securing pawl to bracket-   401—pawl arm-   401A—attachment of pawl arm-   401B—slot in pawl for receiving elastomeric device-   401C—port in pawl-   402—extension arm of pawl-   403—pawl-   403A—stop surface of pawl-   404—pawl cam surface-   404A—pawl curved cam surface-   405—orthodontic molar bracket-   405A, 406—body portion of orthodontic molar bracket-   407—sheath-   408—passageway of pawl-   409—end of upper body portion 406-   410—aperture in body of orthodontic molar bracket-   420—flange of molar bracket-   421—upper surface of molar orthodontic bracket 405-   422—arm of orthodontic molar bracket-   430—studs on pawl extension arm to hold sheath-   450—molar-   452—tooth-   454—base-   455—orthodontic molar bracket-   465—intermediate bracket-   470—notch in pawl-   471—notch in body for opening-   485—elastomeric or metal ligature device-   500—orthographic view of an archwire and orthodontic molar brackets    and teeth illustrating the interrelationship thereof with load    applied to the archwire-   500A—orthographic view of an archwire and orthodontic molar brackets    and teeth illustrating the interrelationship thereof with no load    applied to the archwire-   50OB—enlarged front view of orthodontic molar bracket 455-   50OC—enlarged front view of orthodontic molar bracket with sheath    over pawl extension-   501, 502—loop spring-   580, 581—gap, no load-   590—top side of archwire-   600—perspective view of archwires and brackets applied to teeth of    patient-   600A—side view of archwire and brackets applied to teeth of patient-   700—block diagram of process-   701—attaching a bracket to a tooth-   702—inserting an adjustment portion of the archwire into and through    the passageway of the bracket-   703—attaching one end of an archwire having a loop to an anchor-   704—extending the extendable archwire by applying force to the    archwire by applying force to the archwire to move the adjustment    portion including locking surfaces distally with respect to the    anchor-   705—tensioning the archwire by activating the loop spring-   706—interengaging the pawl and locking surfaces ratcheting and    securing the archwire when the pawl interengages the desired locking    surface of the archwire

Those skilled in the art will recognize that changes may be made to theinvention which has been set forth above by way of example withoutdeparting from the spirit and the scope of the invention as defined bythe claims as set forth below.

1. A method for using an orthodontic device, comprising the steps of:attaching a first bracket to a tooth, said first bracket having apassageway therethrough and a pawl extending into said passageway, and,said pawl includes an extension arm wherein a sheath resides over saidextension arm; attaching one end of an extendable archwire having a loopspring to an anchor; inserting an adjustment portion of said extendablearchwire into and through said passageway of said first bracket, saidadjustment portion includes locking surfaces; extending said extendablearchwire by applying force to said archwire to move said adjustmentportion including said locking surfaces distally with respect to saidanchor; removing said sheath from said extension arm; tensioning saidarchwire by activating said loop spring; interengaging said pawl andrespective ones of said locking surfaces as said adjustment portion isforced through said passageway of said first bracket; and, ratchetingand securing said archwire wherein said pawl interengages a respectivedesired one of said locking surfaces and prevents said loop spring fromretracting said extendable archwire.
 2. A method for using anorthodontic device as claimed in claim 1 wherein said anchor is a secondbracket.
 3. A method for using an orthodontic device as claimed in claim1 wherein said anchor is a band.
 4. A method for using an orthodonticdevice as claimed in claim 1 wherein said anchor is a ligature.
 5. Amethod for using an orthodontic device as claimed in claim 1 whereinsaid anchor is a second bracket which includes a second passageway and asecond pawl, said second pawl includes an extension arm wherein a sheathresides over said extension arm, said archwire includes a second loopspring and a second adjustment portion having locking surfaces, and,further comprising the steps of: inserting said second adjustmentportion of said extendable archwire into and through said secondpassageway of said second bracket, said adjustment portion includinglocking surfaces therein; extending said extendable archwire by applyingforce to said archwire to move said second adjustment portion includingsaid second locking surfaces distally with respect to said firstbracket; removing said sheath from said extension arm; tensioning saidarchwire by activating said second loop spring; interengaging saidsecond pawl and respective ones of said second locking surfaces as saidsecond adjustment portion is forced through said second passageway ofsaid second bracket; and, ratcheting and securing said archwire whereinsaid second pawl interengages a respective desired one of said secondlocking surfaces and prevents said second loop spring from retractingsaid extendable archwire.
 6. A method for using an orthodontic device,as claimed in claim 1 wherein said locking surfaces of said adjustmentportion of said archwire reside in notches.
 7. A method for using anorthodontic device, as claimed in claim 1 wherein said locking surfacesof said adjustment portion of said archwire reside on protrusions.